Cutting tool holder having a resiliently biased retaining means



Oct. 18, 1960 G. A. YATES cu'rwmc TOOL HOLDER HAVING A RESILIENTLYBIASED RETAINING MEANS Flled May 1 1958 mm as mm mm mm L 8 w ml s 0% mMY A E G R 0 E G 44 47 m L, A; ATTORNEY 2,956,792 Patented Oct. 18, 1960United States Patent Ofitice v v 1 79 oo'rrmo 'rooL HOLDER HAVING .Amesm- ENTLY BIASED RETAINING MEANS George A. Yates, 3391 N. Broadway,Grove City, Ohio Filed May 1, 1958, SenNo; 732,395 7 Claims. drapesi'nvention relates 'to a tool holder and more particularly to. at'oolholder havingmeans 'to quicklyremove the tool tl'rerefrom. Y

M'echanization in coal mining operations resolves .itself basically tothe cutting away or disintegrating of the coal'rsearn by 'aiplur'ality tcutter'bits. The cutter bits may be a part of a continuous beringtty emining machine that removes the coal bjy boring an elliptical entry intothe vein of coal. The cutterbitsmay be 'a part of a drum head typecontinuous mining machine having a plurality of horizontal endlesscutter chains arranged adjacent to each other and driven as a uriit.This type of mining machine chips away the coal as it advances into thevein. The 'bits may also be a partof a single endlesscutter chain thatis employed to undercut the. coal in thevein in preparation for. theblasting operation.

, The e'fiieiencybfany of the above mentioned mining machinesdependsupon the sharpness of the multitudes ofcutter .bits securedthereon. Continuous research is being carried onto extend the periodthat a cutter bit canbe efliciently retainedwon the machine. Even withtheadvances that have been made, present-day cutter bit-s remain sharpfor a relatively short period of time and the continuous mining machinemust be shut down and the dull cutter bits removed and replaced with newsharpened bits; The time spent replacing the cutter bits is considerednon-productive in that the machine is not in use and coal is not beingmined during this inactive period. .Any reduction in the down-time of acontinuous mining machine would proportionately increase the tonnage ofcoal mined withthat particular machine.

The conventional method for securing cutter bits in the present bitholders is by means of :a set screw wedging the bit shank against theside wall :of the shank receiving socket. To loosen and retract the setScrew, ipry out the dull bit, insert the shank of anew, sharpened bitand again advance the set screw to wedge against'the new cutter bitshank is a laborious and time consu ming-operation. This is especiallytrue when the operat'ion m ust be repeated tor each of the mauy'cutterbits carried by a continuous mining machine.

To further complicate the bit securing or Wedging 'op eration andprolong the down-time of the continuous miner, there have been instancesreported where the threaded receiving apertures for the set screw havebeen contaminated and damaged or the set screws have been 2 holder andgathered with the dislodged coal. 'Not only is the efliciency of themining machine reduced, but special equipment must then be provided torecover the relatively expensive bits, otherwise machinery used in cleaningflthe coal. may be damaged by the metallic cutter bit,

With my new and. improved bit holder, the time required for thebitych'angin'g operation is materially re 'du'ced. In my construction Ieliminate the; set screw typeiof shank securing, means and in its steadI employ a securing means that, through a wedging action, urgesthefbitishank against the side wall of the tool holder bit socket.Further, I provide an external means to quickly release the shanksecuring means so that the cutter bit may be easily removed. securingmeans includes a cylindrical roller bearing surface that permits theshank of anew, sharp' bit to be inserted into the shank socket withoutexternally releasing the bit securing means .My new, improved bit holdernot only provides a means to quickly remove the cutter bit therefrom,but also sturdily carries the cutter bit so that it performs itscuttingoperation in --afpro.per manner. My cu't'ter bit holder is notaifecte'd" or-contarninated by. coal dust and functions equally-wellunder the severest mining operations. My cutter bit holder is.furt-her'not affected by the vibration of mining machine so that'theloss of cutter bits due to mining machine vibration is materiallyreduced.

Accordingly, the principal object of this invention is to provide a toolholder having a means to secure a tool shank therein:

Another object of this inventionris to provide a tool holder having atool securing means-that may be easily released for tool removal.

'Another object of my invention is "to provide a tool holder in whichthetool securingmeans does-not .loosen because of .machineyibration. 1

Another object of my invention is to-provide a cutter bit holder inwhich the tool securing means is notedversely :atfected' by coal dust orfine coal particles.

Still another object of this invention is to provide a tool holder thatis rugged and simple in construction,-easy to assemble and operate.

This invention comprises the new and improved eonstruct-ion andcombination of parts and their operating relation to each other whichwill be described more fully herein'aftertand the novelty of which willbe particularly pointed out and distinctly claimed.

In' the accompanying drawings, 'to :be taken as part of thisspecification, I have fully and clearly illustrated my invention inwhich drawings:

Figure 1 is a top plan view of a'cutter chain link with the cutter hitsecured in the bit holder.

cross threaded in the set screw receiving apertures, 'so

machine results in the bits being pulled out of the bit Figure 2 is aview in section taken along the line 2- 2 of Figure l and illustratingmy bit securing means section.

:Figure '3 is a fragmentary view in section taken along the :line 3-3 ofFigure 2 and illustrating the upper side wall of the bit shank socket.

"Figure 4 is a fragmentary perspective view of my bit holderillustrating in detail the relative position of the bit shank and thebit securing means.

Figure 5 is a perspective view of my bit shank secure ing means removedfrom the tool hlder.

Figure 6 is an enlarged fragmentary view in section taken substantiallyalong the line 66 of Figure 3 "illustrating the bit securing meanschamber extending into the bit shank socket. I

Referring to the drawings and particularly to Figuresfl and 2, there isillustrated a cutter chaih linlc'generaily indicated by the numeral 11)having a link portion "12, "a bit or tool holder 14, :and a cutter bit16 The "12'' has a pair of :depending parallel portions 18- and 20aligned pintle receiving apertures 22 therethrough and a body portion 24with a single pintle aperture 26 there through. The link 12 is adaptedto be connected in an endless chain by means of pintles or pinsextending through the apertures 22 and 26 in the illustrated link andother overlapping connecting links. The link depending portions 18 and20 have outwardly extending top flanges 28 and 30 which also form thebase for the bit holder 14. Although the bit holder 14 is illustrated asintegrally formed with the chain link 12, the bit holder 14 may also beindependently formed and secured to the flange portions 28 and 30 as bywelding or the like.

The bit holder 14 is of block-like construction and has an upper sidewall 32 and a lower side wall 34. As shown in Figure 2, the bit holderside walls 32 and 34 are in converging relation to each other. The bitholder 14 has a front end wall 36, a rear end wall 38 and a top wall 40(Figure l). Extending longitudinally through the bit holder 14 is a bitshank socket generally designated by the numeral 42. The socket 42 isrectangular in shape and has a top side wall 44, a bottom side wall 46and end walls 48 and 50. The top and bottom side walls 44 and 46 areclearly illustrated in Figure 2, and end walls 48 and 50 are illustratedby dotted lines in Figure 1. The longitudinal axis of the socket 42 isindicated in Figure 2 by the line A-A that extends substantiallyparallel to the bit holder bottom side wall 34. The bit shank socket 42is adapted to receive the rectangular shank of the cutter bit 16. Itshould be noted that the socket 42 is rectangular in section and theshank of cutter bit 16 is also rectangular in section.

The bit holder 14 has a securing means chamber generally designated bythe numeral 52 formed therein. The chamber 52 has a pair of end walls 54and 56 (Figure 1) which are substantially parallel to the socket endwalls 48 and 50. The chamber 52 also has a top wall 58 and a bottom wall60 (Figure 2). The chamber 52 is in juxtaposition with the socket 42 andhas a greater endwise dimension than the socket 42 so that there isformed a pair of bottom rails 62 and 64. The bottom rail 64 is indicatedin dotted lines in Figure 2 and is clearly shown in Figure 6. The bottomrails 62 and 64 support the bit securing means. The longitudinal axis ofthe securing means chamber 52 is indicated by the line B-B in Figure 2.A portion of the chamber 52 extends into the bit shank socket 42 due tothe relation of the longitudinal axes of both the bit shank socket 42and the securing means chamber 52. The portion of chamber 52 thatextends into socket 42 is illustrated in Figures 2 and 6.

The bit holder upper side wall 32 has a T-shaped slot 66 which providesa means for inserting both the bit securing means into chamber 52 andalso for inserting a wedging tool as will later be described. The slot66 extends through upper side wall 32 into chamber 52. The slot 66 formsin the bit holder 14 another wall 68 which serves as a fulcrum for atool to release the bit securing means.

Positioned within the chamber 52 is a bit shank securing means generallyindicated by the numeral 70 (Figure which includes a cylindrical rollerbearing 72 and a flexible or resilient block 74. This block 74 may beconstructed of a rubber material or the like and has a metallic faceportion 76 which is arranged to abut the cylinder 72. As illustrated inFigure 2, the bit shank securing means 70 substantially fills thechamber 52 and urges the roller bearing 72 along the rails 62 and 64into the bit shank socket 42.

The cutter bit 16 has a body portion 78 with a front cutting edge 80 anda rear shoulder portion 82. Extending from the body portion 78 is anenlongated rectangular shank 84. The shank 84 is positioned in the shanksocket 42 and urged downwardly therein until the bit shoulder portion 82abuts the bit holder top wall 40. In this manner the shank portion 84properly positions the cutter bit 16 in the bit or tool holder 14. Theroller bearing 4 72 is urged against one side wall of the bit shank 84by means of the compressed resilient block 74 and wedging the other sideof the bit shank 84 against the socket bottom side wall 46. In thismanner the cutter bit 16 is rigidly secured in the bit holder 14.

Operation To remove the cutter bit 16 from the bit holder 14 a tool suchas a screw driver or the like is inserted through the T-shaped slot 66in the bit holder upper side wall 32 between the roller bearing 72 andthe chamber top wall 58. The wall 68 formed by the T-shaped slot 66serves as a fulcrum for the tool blade. Rotation of the tool in acounterclockwise direction as viewed in Figure 2 will further compressthe resilient block 74 and move the roller bearing in the chamber 52away from the chamber top wall 58. Movement of the bearing 72 upwardlyalong the rails 62 and 64 releases the wedging action of bearing 72 thatwas formerly exerted against the side wall of bit shank 84. The cutterbit 16 may then be easily removed from the bit holder 14 by simplyremoving the bit shank 84 from the bit shank socket 42.

To insert the cutter bit 16 in the bit holder 14, the bit shank 84 isinserted in the socket 42. Although the roller bearing 72 is in theportion of chamber 52 that extends into socket 42, pressure on the bit16 will compress the resilient block 74 and move the roller bearing 72upwardly along the rails 62 and 64- to provide adequate clearance forthe bit shank 84.

As has been described, with my new hit securing means it is a simple,quick operation to remove the bit 16 by simply moving the roller bearing72 in chamber 52 out of the portion of chamber 52 that extends into thesocket 42. This may be accomplished as previously set forth with a screwdriver or the like. It is also a very simple procedure to insert a new,sharp cutter bit by simply urging the roller bearing upwardly by apressure on the cutter bit 16.

Another advantage of my bit securing means 70 is its operability undersevere conditions of contamination. Coal dust or fine coal particles inchamber 52 do not materially afiect the releasing operation of my bitsecuring means. The block 74 of resilient material and the roller 72substantially fill the chamber 52 so that the collection of coal dust orfine coal particles is highly improbable.

According to the provisions of the patent statutes, I have explained theprincipal, preferred construction and mode of operation of my inventionand have illustrated and described what I now consider to represent itsbat embodiment. However, I desire to have it understood that, within thescope of the appended claims, the invention may be practiced otherwisethan as specifically illustrated and described.

I claim:

1. A cutter bit chain link comprising in combination a chain link, saidlink having a cutter bit holder extending laterally therefrom, a cutterbit having a body portion and a shank portion, said shank portion beingrectangular in section, said cutter bit holder having a body portionwith a cutter bit shank receiving socket extending therethrough, saidshank socket being rectangular in section and adapted to receive saidcutter bit shank portion, said cutter bit holder body portion having arectangular chamber formed therein in juxtaposition with said socket,said chamber having its longitudinal axis inclined to the longitudinalaxis of said socket and a portion of said chamber extending into saidsocket, a cylindrical tool securing member positioned in said chamberand having its longitudinal axis transverse to the longitudinal axis ofsaid chamber, a flexible rubber block positioned in said chamber inabutting relation with said tool securing memher, said block arranged tourge said tool securing mem her into said chamber portion extending intosaid socket to thereby urge said cutter bit shank portion against a sidewallof said socket and secure said cutter bit in said bit holder, saidcutter 'bi-t'ho'lder body portion .having a l'-shaped slot extendinginto said chamber, one leg of said slot forming an end wall in saidcutter bit body portion in overlying relation with said chamber portionextending into said socket, :said slot adapted to provide an opening forpositioning said cylindrical .tool securing means and said rubber blockin said chamber, said last named end wall adapted to serve as a for ameans to movesaid tool securing member in said chamber away from saidchamber portion extending into Said socket to thereby release saidcutter bit tool shank.-

A tool holder'having a body portion with a shank receiving sockettherein, a cutting tool having a rectangular shank portion, said socketbeing rectangular in section and adapted to receive said cutting toolshank portion, said tool holder body portion having a rectangularchamber formed therein in juxtaposition with said socket, said chamberhaving its longitudinal axis inclined to the longitudinal axis of saidsocket and a portion of said chamber extending into said socket, aflexible tool securing means positioned in said chamber and extendinginto said shank socket to thereby secure said cutting tool shank portionin said socket by urging said cutting tool shank portion against a sidewall of said socket, said tool securing means including a flexibleblock, said tool holder body portion having a slot extending into saidchamber, said slot spaced from said chamber portion extending into saidsocket, said slot providing an opening for positioning said flexibleblock within said chamber, and said tool holder body portion havingaccess means to said chamber to provide a means to move said flexibletool securing means in said chamber away from said chamber portionextending into said socket to thereby release said cutting tool shankportion.

3. A tool holder having a body portion with a shank receiving sockettherein, a cutting tool having a rectangular shank portion, said socketbeing rectangular in section and adapted to receive said cutting toolshank portion, said tool holder body portion having a rectangularchamber formed therein in juxtaposition with said socket, said chamberhaving its longitudinal axis inclined to the longitudinal axis of saidsocket and a portion of said chamber extending into said socket, aflexible tool securing means positioned in said chamber and extendinginto said shank socket to thereby secure said cutting tool shank portionin said socket by urging said cutting tool shank portion against a sidewall of said socket, said tool holder body portion having a T-shapedslot extending into said chamber, one leg of said slot forming an endwall in said tool holder body portion in overlying relation with saidchamber portion extending into said socket, said slot adapted to providean opening for positioning said flexible tool securing means in saidchamber, said last named end wall adapted to serve as a fulcrum for ameans to move said tool securing means in said chamber away from saidchamber portion extending into said socket to thereby release saidcutting tool shank portion.

4. A tool holder having a body portion with a shank receiving sockettherein, a cutting tool having a rectangular shank portion, said socketbeing rectangular in section and adapted to receive said cutting toolshank portion, said tool holder body portion having a rectangu larchamber formed therein in juxtaposition with said socket, said chamberhaving its longitudinal axis inclined to the longitudinal axis of saidsocket and a portion of said chamber extending into said socket, aflexible tool securing means positioned in said chamber and extendinginto said shank socket to thereby secure said cutting tool shank portionin said socket by urging said cutting tool shank against a side wall ofsaid socket, said tool holder body portion having a T-shaped slot formedtherein with a vertical leg intersecting a horizontal leg, said slotextending into said chamber with said verticalleg forming, an end wallin said tool holder body'lportion in overlying relation with saidchamber ertion extending into said socket, said slot horizontal legspaced from said chamber portion extending into said socket andproviding an opening for positioning. said flexible tool securing meansin said chamber, said last named end wall adapted to serve as a fulcrumfor a means to move said tool securing means in said chamber away fromsaid chamber portion extending into said socket to thereby release saidcutting 'tool shank portion.

' 5. In combination, a cutter bit holder, a cutter bit having' a bodyportion and a shank portion, said shank poi-- tion being rectangular insection, said 'cutter bit holder having a body portion with a cutter bitshank receiving socket extending therethrough, said shank socket beingrectangular in section and adapted to receive said cutter bit shankportion, said cutter bit holder body portion having a rectangularchamber formed therein in juxtaposition with said socket, said chamberhaving its longitudinal axis inclined to the longitudinal axis of saidsocket and a portion of said chamber extending into said socket, acylindrical tool securing member positioned in said chamber and havingits longitudinal axis transverse to the longitudinal axis of saidchamber, a flexible rubber block positioned in said chamber in abuttingrelation with said tool securing member, said block arranged to urgesaid tool securing member into said chamber portion extending into saidsocket to thereby urge said cutter bit shank portion against a side wallof said socket and secure said cutter bit in said bit holder, saidcutter bit holder body portion having a T-shaped slot extending intosaid chamber, one leg of said slot forming an end wall in said cutterbit body portion in overlying relation with said chamber portionextending into said socket, said slot adapted to provide an opening forpositioning said cylindrical tool securing means and said rubber blockin said chamber, said last named end wall adapted to serve as a fulcrumfor a means to move said tool securing member in said chamber away fromsaid chamber portion extending into said socket to thereby release saidcutter bit tool shank.

6. A tool holder having a body portion with a shank receiving sockettherein, a cutting tool having a rectangular shank portion, said socketbeing rectangular in section and adapted to receive said cutting toolshank portion, said tool holder body portion having a rectangularchamber formed therein in juxtaposition with said socket, saidrectangular chamber being greater in lateral extent than said shankreceiving socket, said chamber having its longitudinal axis inclined tothe longitudinal axis of said socket and a portion of said chamberextending into said socket, a flexible tool securing means positioned insaid chamber and extending into said shank socket to thereby secure saidcutting tool shank portion in said socket by urging said cutting toolshank portion against a side Wall of said socket, said tool securingmeans including a flexible block and a cylindrical roller member, saidtool holder body portion having a slot extending into said chamber, saidslot spaced from said chamber portion extending into said socket, saidslot providing an opening for positioning said flexible block and saidcylindrical roller member within said chamber, and said tool holder bodyhaving access means to said chamber to provide a means to move saidflexible tool securing means in said chamber away from said chamberportion extending into said socket to thereby release said cutting toolshank portion.

7. A tool holder having a body portion with a shank receiving sockettherein, a cutting tool having a rectangular shank portion, said socketbeing rectangular in section and adapted to receive said cutting toolshank portion, said tool holder body portion having a rectangularchamber formed therein in juxtaposition with said socket, said chamberhaving its longitudinal axis inclined to the longtudinal axis of saidsocket and a portion of said chamber extending into said socket, aflexible tool secure 7 ing means positioned in said chamber andextending into said shank socket to thereby secure said cutting toolshank portion in said socket by urging said cutting tool shank portionagainst a side wall of said socket, said tool securing means including aflexible block and a cylindrical roller member, said tool holder bodyportion having a slot extending into said chamber, said slot spaced fromsaid chamber portion extending into said socket, said slot providing anopening for positioning said flexible block and said cylindrical rollermember within said chamber, and said tool holder body portion havingaccess means to said chamber, said access means permitting access tosaid chamber portion extending into said socket, said access meansarranged to provide a means to move said flexible tool securing means insaid chamber away from said chamber portion extending into said socketto thereby release said cutting tool shank portion.

References Cited in the file of this patent UNITED STATES PATENTS1,325,029 Morgan Dec. 16, 1919 2,089,166 Reichhardt Aug. 3, 19372,483,032 Baer Sept. 27, 1949 2,576,225 Hostetter Nov. 27, 19512,657,482 Launder et a1. Nov. 3, 1953 2,846,790 Davis et a1. Aug. 12,1958

